Valve

ABSTRACT

A settable control valve ( 13, 50, 113 ) has a closure member moveable within a passage-way ( 17, 71, 81 A,  101, 117 ), there being at least one groove for fluid flow ( 25, 26, 44, 56, 57, 97, 98, 107, 108, 125, 126 ) in the wall of the passageway. The groove is of varying transverse cross-sectional area along its length and the closure member may be set at different positions so as to expose varying lengths of the groove to fluid flow, hence enabling different fluid flow rates to be established.

This invention relates to a valve. It is of particular applicability toa control valve that can be used as a settable coolant flow valve or asa dispense valve for beverages, e.g. to control flow of syrups andcarbonated water to a dispenser. However, it will be appreciated thatthe invention is not limited to valves for such uses.

Thus it is an object of the invention to provide a valve that issuitable for use as a control valve that can be maintained for a periodof time in a partially open configuration or can be used in a situationwhere frequent opening and closing of the valve is required.

It is also an object of the invention to provide a valve which can beset with precision to any position in a desired range of partially openconfigurations between the fully closed and fully open positions andwhich can demonstrate a high degree of flow linearity between the fullyclosed and fully open positions.

Ingress of particles of dirt can cause problems in many valve systems.In addition to getting trapped between valve closure surfaces, wherethey can damage valve ports or seats, dirt particles can obstruct thecross-sectional area available for flow, and thereby alter predictedflow rates for a given valve opening. Thus it will be appreciated thatthis can be a particularly serious problem if a valve is particularlyintended for use in a partially open, set configuration.

It is a further object, therefore, of the present invention, to providean improved control valve in which the problems caused by dirt particlescan be avoided or at least ameliorated.

Accordingly the invention provides a valve, the valve comprising asubstantially rigid housing containing a passageway between an inlet andan outlet of the valve, a closure member movable in the passageway froma first position in which the valve is fully closed to a second positionin which the valve is fully open, the closure member engaging the wallof the passageway to seal the passageway, the wall of the passageway orthe closure member defining at least one groove, the groove having atransverse cross section that increases in area in the downstream orupstream direction, whereby movement of the closure member from thefirst position towards the second position opens a flow channel throughthe groove.

Thus it will be appreciated that flow through the valve in the partiallyto fully open positions is through the groove or grooves.

Preferably the closure member comprises a substantially rigid piston,which may be of the same material as the housing, e.g. of metal,plastics material or ceramic material. Suitably rigid plastics materialsinclude, for example, acetals and acrylonitrile-butadiene-styrene (ABS)copolymers. The grooves may be, for example, cut or moulded into thematerial of the passageway wall or closure member by conventional meansdepending on the material used.

The valve may conveniently be accurately set in any desired positionfrom fully closed to fully open by means of, for example, a levermechanism, a stepper motor, e.g. of the pulsed magnetically driven type,a proportional solenoid activator, a diaphragm operated mechanism, orthe like. When the valve is to be repeatedly opened and closed a steppermotor or proportional solenoid actuator means may be preferred. Steppermotors, for example, can provide particularly accurate incrementalincreases or decreases in flow control.

The closure member may carry one or more sealing rings to engage thewall of the passageway in the first position, i.e. the closure membermay engage the wall of the passageway by means of the sealing ring(s) toclose the outlet. Alternatively, sealing rings for this purpose may belocated in the wall of the passageway. In a yet further embodiment theclosure member and passageway may be a precision fit in the firstposition to close the outlet without a seal.

Accordingly, in one specific embodiment the invention provides a controlvalve, the valve comprising a housing containing a passageway between aninlet and an outlet of the valve, a closure member movable in thepassageway from a first position in which the valve is fully closed to asecond position in which the valve is fully open, the closure membercarrying a seal to engage the wall of the passageway to seal thepassageway, the wall of the passageway defining at least one groove, thegroove being located in the passageway wall downstream of the engagementbetween the wall and the seal in said first position, the groove havinga transverse cross-section that increases in area in the downstreamdirection, whereby movement of the closure member from the firstposition towards the second position opens a flow channel through thegroove.

As indicated above, the valves of the invention are particularly usefulfor incorporation into the dispense head of a beverage dispenser wherethey may be used to control the flow of fluids to be mixed at thedispense valve, e.g. syrup and carbonated water, or they may beincorporated into a coolant manifold for use in cooled beverage dispensesystems. A typical manifold may contain a plurality of valvescontrolling outlets for the coolant, the valves being spaced along acommon manifold. Each valve may comprise a housing containing apassageway from the common manifold to the valve outlet.

In a typical coolant manifold, the passageway of each control valve inthe manifold will usually comprise at least a portion in the form of aright cylinder, and the closure member will be a corresponding cylinderof outside diameter slightly less than the internal diameter of thepassageway, the closure member having an “O”-ring seal attached aroundits outer surface to seal against the passageway wall. In such anarrangement, the grooves may be, for example, a pair of taperingV-shaped grooves opposed across the right cylinder, the cross-section ofeach groove increasing, for example, in the downstream direction. Thegrooves may, of course, have a different tapering cross-section, e.g. ofgenerally circular, rectangular or other shape, but for convenience theinvention will be more specifically described below with reference tothe use of V-grooves although it will be appreciated that it is notintended to be limited thereto.

Depending on the desired particular construction, the V groove orgrooves in the passageway may increase in cross-sectional area in theupstream or downstream direction. In the latter case, the valves havethe added advantage of having greater self-cleaning properties, i.e.larger particles can pass more readily through the valve in the openposition without causing partial blockage than for a conventional valvehaving an annular passageway of the same throughput.

When a conventional valve is used in a partially open position, i.e.between the above-mentioned first and second positions, it will beappreciated that the partially open passageway, in the case of atapering cylindrical passageway, is a narrow annular passageway betweenthe wall and the closure member. In the absence of the groove(s) of theinvention, dirt particles can get trapped in this narrow annularpassageway and thereby partially block the passageway and reduce thedesired throughflow of, e.g. coolant. However, the presence of thegroove(s) of appropriate and increasing cross-sectional area to providethe desired flow rates at different valve openings, enables dirtparticles that would otherwise have been trapped to flow through thegroove(s) leaving the valve unblocked and the rate of flow at therequired level. As the valve opening is gradually increased to full, theincreasing cross-sectional area of the groove(s) enables a dirt particleof a particular size to pass through sooner than it would otherwise havedone or, at any given partial opening of the valve, grit particles oflarger size can pass through than could have done so in a conventionalarrangement without the grooves. The valve can conveniently be flushedto remove any trapped particles by fully opening it.

As indicated above, conveniently the passageway and closure member areof generally cylindrical transverse cross-section and a pair of groovesmay be opposed diametrically across the passageway. However, it will beappreciated that the invention is not limited to such constructions.

Where more than one groove is provided in the passageway, it is notessential that all the grooves are positioned to commence and finish atthe same distance along the passageway.

The progressive increase or decrease in area of the groove flow channelscan provide excellent linear flow through valves of the invention.

Embodiments of the invention will now be described by way of exampleonly with reference to the accompanying drawings in which:

FIG. 1 is an isometric view of a coolant manifold for use in a cooledbeverage dispense system;

FIG. 2 is a cross-section through one of the valves of the manifold ofFIG. 1;

FIG. 3 is a schematic view of a portion of the housing containing thepassageway through the valve of FIG. 2;

FIG. 4 is a schematic section through a partially open valve passagewaywithout a groove of the invention;

FIG. 5 is a similar view to FIG. 4 of a partially open valve passagewayprovided by a groove of the invention;

FIG. 6 is a similar view to FIG. 5 with the valve still partially openbut to a greater extent than in FIG. 5;

FIG. 7 is a diagrammatic illustration in part section of a second valveaccording to the invention;

FIG. 8 is a similar illustration of a third valve of the invention;

FIG. 9 is a similar view of a fourth valve of the invention;

FIG. 10 is a similar view of a fifth valve of the invention;

FIG. 11 is a similar view of a sixth valve of the invention;

FIG. 12 is a view in the direction of arrow A of FIG. 11;

FIG. 13 is a section through a valve of the invention showing onearrangement for accurate setting of the position of the closure memberin the valve;

FIG. 14 is an exploded diagrammatic view showing another arrangement foraccurate setting of the position of the closure member in a valve of theinvention;

FIG. 15 is a diagrammatic view of a pair of V-grooves from a valve ofthe invention;

FIG. 16 is a graph of a flow curve for carbonated water using a valve ofthe invention having a pair of V-grooves of the type illustrated in FIG.15 opposed across the passageway wall and in which the desired positionof the closure member of the valve is achieved using a stepper motor;

FIG. 17 is a section through a yet further valve of the invention;

FIG. 18 is a diagrammatic representation in part section of a heatexchanger having a diaphragm setting mechanism for a valve used in acoolant flow line; and

FIG. 18A is an enlarged view of a portion of FIG. 18.

In FIG. 1, a coolant manifold 10 has a common manifold body 11 definingmanifold passageway 12. Body 11 carries a series of outlet valves 13,each comprising a housing 14 and an outlet 15, and has integral lugs 16by means of which it can be secured in the desired position.

As shown in FIG. 2, outlet 15 of valve 13 is connected to manifoldpassageway 12 by valve passageway 17. Passageway 17 is of rightcylindrical shape and is defined by the lower, cylindrical wall 18 ofhousing 14.

Housing 14 contains a valve closure member 19 having a cylindrical stemportion 20 carrying towards its inlet (lower) end an O-ring 21. Stemportion 20 is of external diameter relative to the diameter of valvepassageway 17 such that its O-ring 21 seals against wall 18.

Stem portion 20 continues into a stepped portion 22 of the closuremember 19 which is of larger diameter than stem portion 20 and seals bymeans of an O-ring 23 against the housing wall 18A at an upper, widercylindrical chamber 17A into which passageway 17 leads. Stepped portion22 of closure member 19 is connected at its end remote from stem portion20 to an Allen key operated means 24 by means of which the closuremember 19 may be set to the desired position, i.e. raised and lowered tofully close, partially open or fully open a flow channel through valvepassageway 17. (A similar setting arrangement is shown and described inmore detail with reference to FIG. 13 below.).

The valve is shown in the almost fully open position in FIG. 2. A pairof opposed grooves 25, 26 is formed in the housing wall 18. Each grooveextends from a point 27 on wall 18 which is downstream of the positionat which O-ring 21 contacts wall 18 in the fully closed position of thevalve, to a point 28 where the wider chamber 17A commences and whichrepresents the fully open position of the valve.

The grooves 25, 26 are of tapering cross-section, as shown more clearlyin FIG. 3, and increase in cross-sectional area in the downstreamdirection. As shown the grooves are of generally “V” cross-section, andthe base 29 of each V-shaped groove extends outwardly, i.e. deepens thegroove, in the downstream direction. The arms of the “V” may also openoutwardly, i.e. the angle of the “V” may increase, along the groove inthe same direction.

FIG. 4 shows a conventional annular valve passageway 30 defined betweena cylindrical valve closure member plug 31 and a cylindrical valve wall32. A particle of dirt 33 is too large to pass through the passageway 30and is trapped, causing a partial blockage of the passageway.

In FIG. 5 a valve according to the invention has a flow channel openedbetween a cylindrical valve plug 41 and cylindrical valve wall 42. Theflow channel is provided by a tapering groove 44 in wall 42, the groovebeing of cross-sectional area at this particular valve openingsufficient to allow through passage to a dirt particle 43 of the samesize as particle 33 in FIG. 4. It should be noted that for a particularcross-sectional flow area (and hence flow rate) identical dirt particleswould be trapped by prior art valves but free to pass through a valveaccording to the invention. This is because the prior art valve flowchannel is annular in shape and hence always has a relatively small(radial) dimension. With the new valve the flow channel is groove shapede.g. a vee or a polygon seen in plan view cut into the side of the valvewall 42.

In FIG. 6, the flow channel is shown for a valve setting of increasedflow rate. The groove 44 is of larger cross-sectional area than in FIG.5, due to the tapering configuration of the groove, allowing throughpassage to an even larger dirt particle 46.

It will be appreciated that in FIGS. 5 and 6 the plug 41 and valve wall42 have been shown for clarity with a slight gap between them althoughin practice they are sealed so as to provide no annular flow passagewaythere between.

Thus in the above embodiments the conventional annular flow passage isreplaced by a groove of dimensions to provide the same required flowrate at any given valve opening and the risk of blockage of the flowchannel is considerably reduced.

In FIG. 7, a valve 50 comprises a closure member in the form of a piston51 in a passageway 52 leading from an inlet 53 to an outlet 54, theoutlet extending at right angles to passageway 52. Fluid flow is in thedirection of the arrows A and B (which direction will be similarlyindicated in other embodiments below.).

Wall 55 of the passageway 52A adjacent inlet 53 is of cylindricalcross-section but with a pair of grooves 56, 57 diametrically opposedacross the passageway. The grooves are of generally V configuration andincrease in cross-sectional area as they extend in the downstreamdirection. A narrower extension 58 of piston 51 is a close sliding fitin passageway 52A.

At its downstream end piston 51 carries a sealing ring 59 in an annulargroove 60. Downstream of groove 60 piston 51 tapers to a narrowerextension 61 which slides in a narrow extension 52B of passageway 52 andengages a sealing ring 62 in the wall of passageway 52B. Sealing ring 62prevents leakage of fluid between piston 51 and the wall of passageway52B beyond outlet 54.

The wall of passageway 52 has a tapered section 63 leading to itsnarrower extension 52B and seal 59 of piston 51 engages section 63 toclose outlet 54 which is downstream thereof.

Piston 51 is moved backwards and forwards in passageway 52 to open andclose the valve by means of its extension 61 being attached to a steppermotor (not shown) or other suitable means. This movement is indicated byarrows C—C.

The V grooves enable precise control of fluid flow with the flow controlband width being indicated between arrows D—D. It has a self-cleaningflow path through the increasing groove cross-section and is pressureclosed, although spring-assistance may be provided, if desired.

It will be noted that the upstream end of extension 58 of piston 51 willbe in the maximum flow position of the V grooves at the moment that seal59 engages wall portion 63 and closes the outlet.

The valve can be retrofitted into existing equipment.

In FIG. 8 valve closure member 70 is a cylindrical piston rod moveablebackwards and forwards as indicated by arrows C—C in a passageway 71between an inlet 72 and an outlet 73. Piston 70 is of constant diameteralong its length and has an annular groove 74 containing a sealing ring75 adjacent its downstream end.

Passageway 71 at inlet end 72 is of greater diameter than piston 70 andnarrows via a stepped wall portion 76 to a narrower portion 71A in whichpiston 70 is a sliding fit and against the wall of which seal 75 sealsin the closed position. A pair of diametrically opposed V grooves 77, 78are provided in the wall defining narrower passage portion 71A, thegrooves commencing at stepped wall portion 76 and narrowing in thedownstream direction.

The upstream end of piston 70 is attached to a stepper motor (not shown)or other means to move the piston to open and close the valve.

The valve provides a gradual increase/decrease in pressure/flow onopening and closing. This construction provides minimal pressure on theseal in the closed position and low torque on the, e.g., stepper motor.There is no end stop load on the motor on closing the valve.

In FIG. 9, the valve closure member is a piston rod 80 of cylindricalconfiguration movable backwards and forwards as indicated by arrows C—Cin a passageway 81 between an inlet 82 and an outlet 83. Piston 80tapers to a narrower nose 80A at its downstream end and nose 80A itselftapers at its downstream end to a flat end surface 84. The taperingportion 85 of the nose leading to the end surface 84 provides thesealing means to close the outlet as is described below.

As with the valve of FIG. 8, passageway 81 at its inlet end is ofgreater diameter than piston 80 and narrows via a stepped wall portion86 to a narrow portion 81A in which piston 80 is a sliding fit. A pairof diametrically-opposed V grooves 87, 88 are provided in the walldefining narrower passage portion 81A, the grooves commencing at steppedwall portion 86 and narrowing in the downstream direction.

The upstream end of piston 80 is attached to a stepper motor (not shown)or other means to move the piston to open and close the valve, openingof the valve allowing flow through grooves 87 and 88.

Passageway portion 81A narrows at its downstream end by means of atapered wall portion 89 and leads thereby to narrower outlet 83. Taperedwall portion 89 and tapered portion 85 of the nose of piston 80 are amating, close tolerance fit in the closed position of the valve, wherebythe outlet is closed without need for a separate sealing ring.

Thus this construction has no sealing ring to wear and provides agradual increase/decrease of pressure/flow on opening and closing of thevalve.

In FIG. 10 is illustrated another valve of the invention that does notrequire a separate sealing ring. The valve closure member is acylindrical piston 90 movable backwards and forwards as indicated byarrows C—C in a passageway 91 between an inlet 92 and an outlet 93.

Again passageway 91 at its inlet end is of greater diameter than piston90 and narrows via a stepped wall portion 96 to a narrower portion 91Ain which piston 90 is a sealing fit. Thus piston 90 is a precision fitinto a bore of passageway portion 91A.

A pair of diametrically opposed V grooves 97, 98 are provided in thewall defining narrower passage portion 91A, the grooves again commencingat stepped wall portion 96 and narrowing in the downstream direction.

Again, the upstream end of piston 90 is attached to a stepper motor (notshown) or other means to move the piston to open and close the valve,opening of the valve allowing flow through grooves 97 and 98.

As with the FIG. 9 construction, this valve may be “seal-less”. It alsoprovides a gradual increase/decrease of pressure/flow on opening andclosing, puts minimal pressure on the sealing surfaces when closed andlow torque on the motor and has no end stop loading on the motor.

In FIG. 11, the closure member is a cylindrical piston 100 movablebackwards and forwards (in the direction C—C) in a passageway 101between an inlet 102 and an outlet 103 which leads off at right anglesfrom passageway 101 partway along the length of the piston.

The wall defining passageway 101 has a pair of diametrically-opposed Vgrooves 107, 108 between the inlet and an annular chamber 104 from whichoutlet 103 leads off. The grooves widen in the downstream direction tobe at their widest as they reach chamber 104, which chamber forms partof and lies centrally of passageway 101.

The walls of passageway 101 define a pair of annular recesses 105, 106,each recess carrying a sealing ring 109, 110, respectively.

Recess 105 and its sealing ring 109 lie at the upstream end of V sectiongrooves 107, 108, and piston 100 seals against ring 109 in the valveclosed position. The seal 109 and the grooves 107 and 108 are sopositioned that the upstream end of each V groove commences justdownstream of the seal to prevent hydraulic lock occurring on the valveclosing. As can be seen in FIG. 12, from which the seal 109 has beenremoved for clarity, the upstream ends 107A, 108A of grooves 107 and 108just extend to breakthrough the downstream wall 105A of recess 105.

Recess 106 and its sealing ring 110 are positioned in passageway 101beyond chamber 104 and outlet 103 and the piston 100 is a slidingsealing fit in ring 110 as it moves to open and close the valve.

Again, this construction provides gradual opening and closing of thevalve, the sealing rings are subjected to little wear and the V groovesare self-cleaning in the flow direction shown.

All the above valves of the invention provide a combined flow controland cut off means in a small compact, retro-fittable unit.

The flow direction may, if desired be reversed in each of the aboveembodiments but it will be appreciated that the improved self-cleaningeffect will be achieved only where the V grooves broaden in thedirection of flow.

In FIG. 13 valve 113, which is similar in general construction to thevalve of FIG. 2, comprises a housing 114 and controls flow from manifoldpassageway 112 to an outlet 115 via a lower narrower valve passageway117 and an upper wider passageway 117A, defined by walls 118 and 118Arespectively. A valve closure member 119 can be raised or lowered by amechanical setting mechanism to be described in more detail belowbetween a fully open position, as illustrated, and a fully closedposition respectively. The passageway wall 118 contains a pair ofopposed V-grooves 125, 126 which increase in cross-section in thedownstream direction and the valve operates in a similar manner to thatdescribed with reference to FIG. 2.

Closure member 119 has an annular upper portion 119A which is a slidingfit along passageway wall 118A and a narrower tail portion 119B, whichis a sliding fit in passageway wall 118. Adjacent its lower end, tailportion 119B has an annular recess 119C to carry an O-ring (not shown)to seal against wall 118 below the V-grooves in the fully closedposition of the valve.

The setting of the closure member 119 is operated as follows. At itsupper end housing 114 continues into a hollow cylindrical extension 127which contains a tightly press-fitted internally-threaded cylindricalbush 128. An externally-threaded hollow cylindrical insert 129 isthreadingly engaged inside bush 128. Bush 128 carries an internal thread128A for the whole of its length whereas insert 129 has an externalthread 129A only for a short portion of its length at its upper end.Insert 129 is connected to the upper end of closure member 119 by aconnection member 130 of smaller diameter than the diameters of insert129 and closure member 119. This results in an annular recess 131surrounding connection member 130. This recess can carry an O-ring (notshown) to seal against flow. Insert 129, connection member 130 andclosure member 119 may be integrally formed as a single unit.

The hollow interior 132 of insert 129 is shaped to receive an Allen key(not shown). Rotation of insert 129 by means of an Allen key moves theinsert upwardly or downwardly relative to bush 128 by the threadedengagement therebetween and thereby raises and lowers closure member119. The diameter of insert 129 below its threaded portion is the sameas the diameter of upper portion 119A of the closure member 119 and sois a sliding fit to move up and down inside passageway wall 118A.

When insert 129 is rotated to its lowest position the valve is fullyclosed. Movement of the insert in an upward direction is limited by aninwardly depending flange 128B at the upper end of bush 128 againstwhich insert 129 engages when the valve is in the fully open position.

By this means the valve can be accurately set in a continuous sequenceof gradually increasing or decreasing partially open configurationsbetween fully closed and fully open.

It will be appreciated that this mechanical setting construction may bevaried in a number of ways while achieving the same effect. For example,it is possible to dispense with separate bush 128 and to provide athread on the internal wall of cylindrical extension 127 to co-operatewith the thread on insert 129.

In FIG. 14 is shown schematically an arrangement for opening and closinga valve in a series of accurate steps using a conventional steppermotor.

Stepper motor 140 has a centrally-disposed stepped recess 141 into whichstepped rotor 143 sits and where rotor 143 is caused to rotate in aclockwise or anti-clockwise direction as the windings 142 of the motorare pulsed appropriately and as is conventionally well known.

Rotor 143 contains a threaded centrally-disposed passageway 144extending upwardly from its lower face.

A connection rod 145 has an upper threaded portion 146 of dimensions tothreadingly engage inside the threaded passageway 144 and a lowerextension 147 having an end portion 148 of dimensions to engage in asocket 149 in the end face of a valve closure member 150. A threadedengagement is shown in socket 149, although this is not essential.

Rod 145 is attached by conventional means (not shown) to the steppermotor 140 whereby when rotor 143 rotates within the stationary windings142, rod 145 cannot rotate with the rotor. Thus when rotor 143 rotatesin recess 141, threaded rod portion 146 is forced to move upwardly ordownwardly within passageway 144. Thus the rotational movement of rotor143 is translated into linear movement of rod 145, which moves upwardlyor downwardly as the rotor rotates in a clockwise or anti-clockwisedirection. By means of this linear movement of rod 145, closure member150 is correspondingly moved upwardly or downwardly. (As there is norotational movement of rod 145, the threaded engagement between endportion 148 and socket 149 is unaffected by the rotation of the rotor.).

The stepper motor rotor can be controlled by electronic pulses to rotatein a series of incremental steps and each step represents a particularpartially open valve position. The number of steps can be large, e.g.several hundreds, whereby very accurate positioning of the closuremember can be achieved, thereby giving very accurate flow control.

A typical pair of V-grooves 160, 161 is shown in FIG. 15, being opposedacross a cylindrical passageway wall 162. The grooves have a length “l”and open at an angle “α”. The passageway 162 has a diameter “d” and thediameter at the wider end of the grooves is “D”. As shown, the narrowend of the grooves aligns with one end of the passageway to give anoverall passageway diameter of “d¹”, d¹ being slightly larger than d.

These dimensions may vary widely depending on the particular flowrequirements desired and the skilled man of the art will readily be ableto determine the desired combination of dimensions for his particularrequirements. By way of example only, angle α may be from 1° to 20° butd, d¹ and l can vary widely.

In a specific example, the following dimensions were used:

α=10°;

l=10.82 mm;

d=6.18 mm;

d¹=6.55 mm; and

D=11.0 mm.

A valve of the invention was set to open and close using a stepper motoras described above with reference to FIG. 14. The stepper motor wasarranged to provide 328 steps between the fully open and fully closedvalve positions. The full linear travel of the closure member was 10.82mm so that each step moved the closure member 10.82÷328=0.033 mm. Thisis illustrated graphically in FIG. 16 which plots flow rate in ml/secagainst the number of steps of rotation of the stepper motor. The valvewas used to control flow of carbonated water at 80 psi supply pressure.(This is a typical operational pressure but it can vary widely, e.g.from 40 to 120 psi.).

Each step shown on the graph actually represents four steps in practice.

As can be seen, the flow curve closely approaches perfect linearity andthis clearly demonstrates the excellent stepped flow control that can beachieved over a large number of incremental steps using this arrangementof the invention.

Thus the valves of the invention give excellent linear flow control fromfull flow to little or no flow. Moreover, the valves do not requireexcessive force to open and close them as they do not act against theprevailing fluid pressure. They do not need to draw power whilst not inuse, in contrast to some known types of dispense valve.

In FIG. 17 is shown in sectional view another valve arrangement of theinvention.

The valve 170 comprises a closure member 171 in a housing 172. Housing172 has an inlet 173 and an outlet 174 for through flow of a fluid whenthe valve is partially or fully open. Closure member 171 has a flowgroove configuration comprising V-grooves 175, 176 similar to thosedescribed above and will, therefore, not be described in detail here.

The valve is shown in the fully closed position with O-ring seal 177adjacent a first end of closure member 171 sealing against an annularledge 178 in the interior wall of the housing to prevent through flow.Adjacent its other second end, the closure member carries a pair ofO-ring seals 179, 180 to prevent leakage between that end of the closuremember and the wall of the housing. Movement of the closure member fromleft to right opens the valve.

The closure member is held in the closed position by a springarrangement indicated at 181 and can be opened against the springpressure by an actuator, to be described in more detail below, up to anamount determined by a setting mechanism indicated generally at 181. Thesetting mechanism, which is shown sealed into the housing 172 by O-rings183 and 184, may be of any desired type. Thus, as indicated previously,it may be, for example, of the Allen key-operated type as describedabove with reference to FIG. 13, a stepper motor-operated type asdescribed above with reference to FIG. 14, a proportional solenoidactivator, a diaphragm-operated mechanism or a lever arrangement, andneed not, therefore, be described in detail here.

The valve is actuated by an actuator mechanism indicated generally at185. As shown, this is a “clip-on” gas pressure, e.g. CO₂, operatedactuator. On actuation, CO₂ or other gas enters the actuator via itsinlet 186 and the gas pressure forces a plunger 187 inside the actuatorto move to the right, the plunger slidingly passing through an opening188 in an end wall 189 of the actuator. The distal end of the plunger isin contact with the aforesaid second end of the valve closure member 171and forces it to open against the pressure of spring 181 as far as thesetting allowed by the setting mechanism 182. On ceasing actuation, gasflow ceases and the spring returns the valve to the closed position.

It will be appreciated that the spring controlled closure means actingon the closure member may be replaced by other means. For example, theplunger may be attached to the closure member to pull the closure memberto the fully closed position when actuation ceases.

When the valve is used to control the flow of carbonated water, it isimportant that as little CO₂ as possible is forced out of solution inthe water by the dispensing process through the valve, i.e. excess CO₂“break out” must be avoided. As shown in FIG. 17, the carbonated waterenters via inlet 173 into chamber 190 on the upstream side of closuremember 171. The pressure drop between chamber 190 and inlet 173 may besufficiently great to cause enough “break out” to result in asub-standard drink. To avoid this happening, a restrictor 191 has beenpositioned across the outlet 174, i.e. on the downstream side of theclosure member. This has the effect of reducing the overall pressuredrop from the inlet to the outlet and thereby assists retention of CO₂in the liquid passing through the valve.

The restrictor 191 may be, for example, a porous filter, an orifice or afixed restrictor tube. Alternatively, it may be an adjustable restrictorwhich can be adjusted, e.g. automatically by a suitable control system.

The gas-operated actuator mechanism shown in FIG. 17 may be replaced byany other suitable actuator mechanism. For example, the actuation may beby a simple manual push arrangement, a lever actuator or a steppermotor.

In FIG. 18 is shown a heat exchanger 200 to cool a fluid F, whose flowis indicated by double-headed arrows, by means of a coolant C, whoseflow is indicated by single-headed arrows. The fluid F may be, forexample, a beverage to be dispensed and coolant C a conventionalglycol/water mixture.

The heat exchanger 200 comprises an annular upper housing 201 and alower body 202 through which the coolant can pass. Upper housing 201contains a chamber 203 defined by an annular wall 204, the upper surface205 of body 202 and a diaphragm 206 clamped around its perimeter to thetop of wall 204 by a bell housing 207.

The fluid F can flow via an inlet 208 into chamber 203 and can exit thechamber via an outlet 209, both inlet and outlet being in wall 204.

Coolant C circulates from around a continuous loop GHIJ that includes aconventional refrigeration means (not shown). The loop has a branch 210whereby coolant can flow into and through heat exchanger body 202 and,passing via a valve 211 of the invention, can exit the body 202 toreturn via a one way valve 212 to the loop at point I.

Valve closure member 213 is movable upwardly and downwardly as indicatedby arrows C—C and is shown in its uppermost, valve closed position. Thevalve 211 comprises a passageway between a coolant inlet 214 and outlet215 in the body 202. The passageway wall defines a pair of opposedgrooves 216, 217 which broaden in the downstream direction. This isshown more clearly in FIG. 18A where it can also be seen that, adjacentits lower end, the closure member 213 has an annular groove 218containing an O-ring 219 to seal against the wall of the passageway inthe valve closed position.

The permitted degree of opening of the valve is set by a spring-loadedmechanism acting on diaphragm 206. The spring 220 is mounted inside bellhousing 207 between an upper steel plate 221 and a lower steel plate 222and sits on top of the diaphragm 206 with plate 222 in contact with thediaphragm. The spring is attached to the upper end of closure member 213by means of a rivet or screw-threaded attachment 223 which passesthrough a central aperture in diaphragm 207.

The upper steel plate 221 is contacted by the lower end of an adjustingscrew 224 which passes through an aperture in the wall of the bellhousing. Rotation of screw 224 moves it upwardly or downwardly whereby alesser or greater compression force is applied to spring 220 throughplate 221. This force is transmitted through plate 222 to the diaphragm207. The amount of this force determines the degree to which the valve211 can open, i.e. it sets the valve position.

When fluid F is not being dispensed, chamber 203 is full of fluid F at apressure of, for example 30 to 70 p.s.i. This fluid pressure balancesthe force applied to diaphragm 207 and the valve is closed. When fluid Fis dispensed through outlet 209, e.g. by conventional means not shown,the fluid pressure in chamber 203 drops and the pressure from the springon the diaphragm moves the closure member 213 downwardly to open thevalve to the predetermined position. This allows coolant C to flowthrough the valve to apply cooling effect to the fluid F in chamber 203.Thus the degree of cooling applied is automatically adjusted to the needdetermined by the rate of frequency of drawing off fluid F.

When the flow of fluid F is stopped, the pressure in chamber 203 returnsto its original value, the diaphragm is forced upwardly to recompressthe spring to its original setting and the closure member is therebymoved upwardly to close the valve.

Valves of the invention may find applicability in a wide variety offluid dispense arrangements.

They can be utilised as simple mechanical valves to dispense, e.g., asingle syrup flavour, with delivery controlled by, e.g., pneumatic pushbutton operation, mechanical lever operation or diaphragm operation.

They can be utilised in the single flavour arrangements with or withoutportion control or flow sensing or in multi-flavour delivery systemswith similar controls

What is claimed is:
 1. A flow control valve for controlling the flowrate of a liquid in a down stream direction from an inlet to and out ofan outlet thereof, the flow control valve, comprising: a housing bodydefining a flow passage extending there through from the inlet to theoutlet, and the flow passage having a flow control portion defined by aflow orifice, flow orifice sidewalls, and one or more grooves formed inthe flow orifice sidewalls, and the one or more grooves having across-sectional area that decreases in a downstream direction along theflow orifice sidewalls, a rod extending through the housing and into andsubstantially coextensive with the flow passage and the rod linearlymoveable by a linear drive means, the linear drive means electricallyoperable on command to relatively accurately and repeatedly move the rodto a plurality of positions, and the rod having a distal end portionopposite from the linear drive means for insertion into the flow orificeand the rod distal end portion having exterior sidewalls sized to lieclosely adjacent the flow orifice sidewalls for substantially preventingfluid flow there between and the distal end portion for cooperating witha seat means positioned downstream of the flow passage control portionto prevent liquid flow through the flow passage when the rod is moved toa fully extended position by the linear drive means and the rod alsomoveable thereby to a fully retracted position for permitting maximumliquid flow and the linear drive means for moving the rod distal endportion to a plurality of positions along the one or more grooves forregulating the flow rate of the liquid as a function of thecross-sectional area of the one or more grooves.
 2. The flow controlvalve as defined in claim 1, and the flow passage comprised of a firstupstream leg section and a second downstream leg section, and the firstand second flow passage leg sections extending transversely to eachother and the flow control portion located within the second leg sectionand the rod substantially coextensive with the second leg section. 3.The flow control valve as defined in claim 1, one or more of said valveshaving the one or more outlets thereof fluidly connected to a commonmanifold.
 4. A flow control valve for controlling the flow rate of aliquid in a down stream direction from an inlet to and out of an outletthereof, the flow control valve, comprising: a housing body defining aflow passage extending there through from the inlet to the outlet, andthe flow passage having a flow control portion defined by a floworifice, flow orifice sidewalls, and one or more grooves formed in theflow orifice sidewalls, and the one or more grooves having across-sectional area that increases in a downstream direction along theflow orifice sidewalls, a rod extending through the housing and into andsubstantially coextensive with the flow passage and the rod linearlymoveable by a linear drive means, the linear drive means electricallyoperable on command to relatively accurately and repeatedly move the rodto a plurality of positions, and the rod having a distal end portionopposite from the linear drive means for insertion into the flow orificeand the rod distal end portion having exterior sidewalls sized to lieclosely adjacent the flow orifice sidewalls for substantially preventingfluid flow there between and the rod distal end portion for cooperatingwith a seat means positioned upstream of the flow passage controlportion to prevent liquid flow through the flow passage when the rod ismoved to a fully extended position by the linear drive means and the rodalso moveable thereby to a fully retracted position for permittingmaximum liquid flow and the linear drive means for moving the rod distalend portion to a plurality of positions along the one or more groovesfor regulating the flow rate of the liquid as a function of thecross-sectional area of the one or more grooves.
 5. The flow controlvalve as defined in claim 4, and the flow passage comprised of a firstupstream leg section and a second downstream leg section, and the firstand second flow passage leg sections extending transversely to eachother and the flow control portion located within the first leg sectionand the rod substantially coextensive with the first leg section.
 6. Theflow control valve as defined in claim 4, and one or more of said valveshaving the one or more outlets thereof fluidly connected to a commonmanifold.
 7. A flow control valve for controlling the flow rate of aliquid in a down stream direction from an inlet to and out of an outletthereof, the flow control valve, comprising: a housing body defining aflow passage extending there through from the inlet to the outlet, andthe flow passage having a flow control portion defined by a flow orificeand flow orifice sidewalls, a rod extending through the housing and intoand substantially coextensive with the flow passage and the rod linearlymoveable by a linear drive means, the linear drive means electricallyoperable on command to relatively accurately and repeatedly move the rodto a plurality of positions, and the rod having a distal end portionopposite from the linear drive means for insertion into the flow orificeand the rod distal end portion having exterior sidewalls sized to lieclosely adjacent the flow orifice sidewalls for substantially preventingfluid flow there between, and one or more grooves formed in the roddistal end portion exterior sidewalls, and the one or more grooveshaving a cross-sectional area that decreases in a downstream directionalong said end portion exterior sidewalls and the rod distal end portionfor cooperating with a seat means positioned downstream of the flowpassage control portion to prevent liquid flow through the flow passagewhen the rod is moved to a fully extended position by the linear drivemeans and the rod also moveable thereby to a fully retracted positionfor permitting maximum liquid flow and the linear drive means for movingthe rod distal end portion to a plurality of positions along the floworifice sidewalls for regulating the flow rate of the liquid as afunction of the cross-sectional area of the one or more grooves.
 8. Theflow control valve as defined in claim 7, and the flow passage comprisedof a first upstream leg section and a second downstream leg section, andthe first and second flow passage leg sections extending transversely toeach other and the flow control portion located within the second legsection and the rod substantially coextensive with the second legsection.
 9. The flow control valve as defined in claim 7, and one ormore of said valves having the one or more outlets thereof fluidlyconnected to a common manifold.
 10. A flow control valve for controllingthe flow rate of a liquid in a down stream direction from an inlet toand out of an outlet thereof, the flow control valve, comprising: ahousing body defining a flow passage extending there through from theinlet to the outlet, and the flow passage having a flow control portiondefined by a flow orifice and flow orifice sidewalls, a rod extendingthrough the housing and into and substantially coextensive with the flowpassage and the rod linearly moveable by a linear drive means, thelinear drive means electrically operable on command to relativelyaccurately and repeatedly move the rod to a plurality of positions, andthe rod having a distal end portion opposite from the linear drive meansfor insertion into the flow orifice and the rod distal end portionhaving exterior sidewalls sized to lie closely adjacent the flow orificesidewalls for substantially preventing fluid flow there between and therod distal end portion exterior sidewalls having one or more groovesformed therein, and the one or more grooves having a cross-sectionalarea that increases in a downstream direction along said end portionexterior sidewalls and the rod distal end portion for cooperating with aseat means positioned upstream of the flow passage control portion toprevent liquid flow through the flow passage when the rod is moved to afully extended position by the linear drive means and the rod alsomoveable thereby to a fully retracted position for permitting maximumliquid flow and the linear drive means for moving the rod distal endportion to a plurality of positions along the flow orifice sidewalls forregulating the flow rate of the liquid as a function of thecross-sectional area of the one or more grooves.
 11. The flow controlvalve as defined in claim 10, and the flow passage comprised of a firstupstream leg section and a second downstream leg section, and the firstand second flow passage leg sections extending transversely to eachother and the flow control portion located within the first leg sectionand the rod substantially coextensive with the first leg section. 12.The flow control valve as defined in claim 10, and one or more of saidvalves having the one or more outlets thereof fluidly connected to acommon manifold.
 13. A flow control valve for controlling the flow rateof a liquid in a down stream direction from an inlet to an outletthereof, the flow control valve, comprising: a housing body defining afirst flow passage extending from the inlet and having a distal endportion, a proximal end portion and a piston chamber portion therebetween, a second flow passage extending transverse to the first flowpassage and in fluid communication with the proximal end portion thereofand the outlet, the first flow passage distal end portion having a floworifice, flow orifice sidewalls, and one or more grooves formed in theflow orifice sidewalls, and the one or more grooves having across-sectional area that decreases in an upstream direction along theflow orifice sidewalls, a rod sealingly extending through the housingand into and substantially coextensive with the first flow passage andthe rod linearly moveable by a linear drive means, the linear drivemeans electrically operable on command to relatively accurately andrepeatedly move the rod to a plurality of positions, and the rod havinga distal end portion for insertion into the flow orifice and the roddistal end portion having exterior sidewalls sized to lie closelyadjacent the flow orifice sidewalls for substantially preventing fluidflow there between, and the rod having a proximal portion forming a flowcavity between said rod proximal end and the proximal end of the firstflow passage, and the rod having a piston portion positioned there alongwithin the piston chamber, and the rod piston including sealing meansfor seating against the first flow passage proximal end for stopping theflow of liquid when the rod is moved by the linear drive means to afully retracted position, and the rod also moveable thereby to aplurality of positions along the one or more grooves for regulating theflow rate of the liquid as a function of the cross-sectional area of theone or more grooves.
 14. The flow control valve as defined in claim 13,and one or more of said valves having the one or more outlets thereoffluidly connected to a common manifold.